Linalool elicits vasorelaxation of mouse aortae through activation of guanylyl cyclase and K+ channels

Objectives

The aim of this study was to investigate the cardiovascular relaxing properties of monoterpene alcohol (-)-linalool (LIN), a principal component of several aromatic plants.

Methods

We assessed the effects of LIN on vascular contractility in mouse aortae and evaluated its underlying mechanisms of action.

Key findings

We found that LIN dose-dependently relaxed the vascular tonus of mouse thoracic aortae induced by prostaglandin F2 alpha (PGF2α, 3 μm). This effect, however, was reduced by pretreatment with the nitric oxide synthase inhibitor L-NAME (30 μm). Treatment with the inhibitor of soluble guanylyl cyclase ODQ (2 μm) or the K+ channel blocker TEA (10 mM) partially blocked LIN-induced vasorelaxation. Moreover, addition of TEA after incubation of the rings with L-NAME and ODQ partially blocked LIN-induced vasorelaxation. Furthermore, LIN was able to partially antagonize CaCl2-induced contractions in high potassium (80 mM) Krebs' solution, whereas LIN did not affect Ca2+ release from endoplasmic reticulum Ca2+ stores.

Conclusion

Our findings indicate that LIN may induce endothelium-dependent vasorelaxation in mouse thoracic aortae by activating soluble guanylyl cyclase and K+ channels.

Effects of Salvia sclarea on chronic immobilization stress induced endothelial dysfunction in rats

Background

Although Salvia sclarea (clary sage) is widely used in aromatherapy and has antioxidant and antimicrobial properties, its mechanisms of action remain poorly understood. We therefore assessed whether clary sage is effective in treating endothelial dysfunction induced by chronic immobilization stress in rats.

Methods

Rats were intraperitoneally injected with almond oil, clary sage oil (5%, 10% or 20%), or nifedipine once daily, followed by immobilization stress (2 h/day) for 14 days. Systolic blood pressure (SBP) and heart rate (HR) were measured, as were serum concentrations of corticosterone (CORT); a biomarker of chronic stress, malondialdehyde (MDA); a biomarker of oxidative stress. Nitric oxide production was assessed by nitrite assays, and eNOS level, a biomarker of endothelial dysfunction, was measured by western blotting. Endothelial dysfunction was also assayed by measuring the effect of clary sage on the contraction of rat aortae.

Results

Treatment with 5% (p = 0.029), 10% (p = 0.008), and 20% (p = 0.008) clary sage significantly reduced SBP and treatment with 20% clary sage significantly reduced HR (p = 0.039) compared with the chronic immobilization stress group. Clary sage decreased CORT serum concentration (10%, p = 0.026; 20%, p = 0.012) and MDA (10%, p = 0.007; 20%, p = 0.027), findings similar to those observed with nifedipine. In addition, 20% clary sage significantly increased nitric oxide production (p <0.001) and eNOS expression level (p <0.001) and relaxed aortic rings in rats subjected to chronic immobilization stress.

Conclusions

Clary sage treatment of rats subjected to immobilization stress contributed to their recovery from endothelial dysfunction by increasing NO production and eNOS level as well as by decreasing oxidative stress. Appropriate concentration of clary sage may result in recovery from endothelial dysfunction. These findings indicate that clary sage oil may be effective in the prevention and treatment of stress-induced cardiovascular diseases.

RNA-seq analysis of the rat placentation site reveals maternal obesity-associated changes in placental and offspring thyroid hormone signaling

INTRODUCTION

In animal models, maternal obesity (OB) leads to augmented risk of offspring OB. While placental function is influenced by maternal habitus, the effect of maternal obesity on the interacting zones of the placenta [the labyrinth (LZ), junctional (JZ) and metrial gland (MG)] remains unknown.

METHODS

Using a rat maternal obesity model, we conducted transcriptomic profiling of the utero-placental compartments and fetal liver (FL) at dpc 18.5, in conjunction with analyses of mRNA expression of key thyroid hormone (TH) signaling genes in the placenta, fetus and weanling offspring.

RESULTS AND DISCUSSION

Gene expression analysis of placenta and offspring revealed that each utero-placental compartment responds distinctly to maternal OB with changes in inflammatory signaling, lipid metabolism and hormone stimulus being the predominant effects. OB-induced alterations in 17 genes were confirmed by qPCR, including reductions in thyrotropin-releasing hormone (Trh) in JZ. We further characterized mRNA and protein expression of TH signaling regulators including deiodinases (Dio), TH receptors (Tr), and downstream targets (uncoupling proteins (Ucp)). A concerted down-regulation of multiple facets of thyroid hormone signaling in the JZ and FL was observed. JZ expression of thyroid hormone signaling components Trh, Dio2, Trα, and Ucp2 were negatively associated with maternal leptin. mRNA expression of TRH, TRβ and UCP1 were also decreased in term placenta from OB women. Finally, our studies identified persistent impairments in expression of TH related genes in tissues from offspring of obese dams.

CONCLUSIONS

The role of lower placental thyroid expression is worthy of further study as a possible pathway that leads to low energy metabolism and obesity in animals born to obese mothers.

Effects of 1,8-cineole on hypertension induced by chronic exposure to nicotine in rats

Objectives

The monoterpenic oxide 1,8-cineole is a major component of many essential oils. We investigated its effects on systolic blood pressure (SBP) and oxidative stress in rats chronically exposed to nicotine.

Methods

Male Sprague–Dawley rats (100–120 g) were intraperitoneally injected with 0.8 mg/kg/day nicotine for 21 days, followed by 3 mg/kg nicotine the next day. Rats were subsequently injected intraperitoneally with 0.01, 0.1 and 1 mg/kg 1,8-cineole, or 10 mg/kg nifedipine. SBP was measured using a tail cuff transducer, plasma nitrite concentration was measured colorimetrically, and plasma corticosterone concentration was measured by enzyme immunoassay.

Key findings

We found that 0.1 mg/kg 1,8-cineole significantly reduced SBP, and that 1.0 mg/kg 1,8-cineole significantly increased plasma nitrite concentrations, compared with rats chronically exposed to nicotine alone. Rats chronically exposed to nicotine showed a significant increase in lipid peroxidation levels, an elevation significantly antagonized by treatment with 0.01 mg/kg and 0.1 mg/kg 1,8-cineole. Chronic exposure to nicotine also significantly increased plasma corticosterone levels, but this effect was not diminished by treatment with 1,8-cineole.

Conclusions

These results indicate that 1,8-cineole may lower blood pressure, and that this antihypertensive effect may be associated with the regulation of nitric oxide and oxidative stress in rats chronically exposed to nicotine.

Anti-inflammatory effects of anethole in lipopolysaccharide-induced acute lung injury in mice

AIMS

Anethole, the major component of the essential oil of star anise, has been reported to have antioxidant, antibacterial, antifungal, anti-inflammatory, and anesthetic properties. In this study, we investigated the anti-inflammatory effects of anethole in a mouse model of acute lung injury induced by lipopolysaccharide (LPS).

MAIN METHODS

BALB/C mice were intraperitoneally administered anethole (62.5, 125, 250, or 500 mg/kg) 1 h before intratracheal treatment with LPS (1.5 mg/kg) and sacrificed after 4 h. The anti-inflammatory effects of anethole were assessed by measuring total protein and cell levels and inflammatory mediator production and by histological evaluation and Western blot analysis.

KEY FINDINGS

LPS significantly increased total protein levels; numbers of total cells, including macrophages and neutrophils; and the production of inflammatory mediators such as matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nitric oxide (NO) in bronchoalveolar lavage fluid. Anethole (250 mg/kg) decreased total protein concentrations; numbers of inflammatory cells, including neutrophils and macrophages; and the inflammatory mediators MMP-9, TNF-α and NO. In addition, pretreatment with anethole decreased LPS-induced histopathological changes. The anti-inflammatory mechanism of anethole in LPS-induced acute lung injury was assessed by investigating the effects of anethole on NF-κB activation. Anethole suppressed the activation of NF-κB by blocking IκB-α degradation.

SIGNIFICANCE

These results, showing that anethole prevents LPS-induced acute lung inflammation in mice, suggest that anethole may be therapeutically effective in inflammatory conditions in humans.

An animal model of Kashin-Beck disease induced by a low-nutrition diet and exposure to T-2 toxin

OBJECTIVE

We investigated the combined roles of a low-nutrition diet (low levels of protein, iodine, and selenium) and T-2 toxin in bone development and to establish an experimental animal model of Kashin-Beck disease (KBD) that reliably mimics the disease's pathological changes for further study of the pathogenesis and prevention of the disease.

METHODS

Sprague-Dawley rats were randomly divided among four groups: group A, normal diet; group B, normal diet plus T-2 toxin; group C, low-nutrition diet; and group D, low-nutrition diet plus T-2 toxin exposure. The radiographic and histopathological changes in the tibial growth zone, plate cartilage and metaphysis were examined.

RESULTS

In group D, all epiphyseal plates were blurred, thin, and irregular. Tibias were significantly shorter in group D than in groups A and B. After 4 weeks, epiphyseal plates showed chondrocyte necrosis, with the more obvious necrosis appearing in groups C and D. The positive rate of lamellar necrosis was significantly higher in group D than in groups B and A (P < 0.01). In group D, metaphyseal trabecular bone was sparse, disordered, and disrupted, and massive transverse trabecular bone appeared in the metaphysis at 12 weeks.

CONCLUSIONS

A rat model of KBD induced by a low-nutrition diet and T-2 toxin exposure demonstrated radiographic and histopathological abnormalities of the proximal epiphyseal plate and the tibial metaphysis that are very similar to the bone changes found in patients with KBD. This animal model will be helpful for further study of the pathogenesis and prevention of KBD.

Autologous dendritic cells combined with cytokine-induced killer cells synergize low-dose chemotherapy in elderly patients with acute myeloid leukaemia

OBJECTIVES

To investigate the possibility of culturing dendritic cells (DCs) and cytokine-induced killer (CIK) cells, obtained at initial diagnosis of AML in elderly patients, and to investigate the safety and efficacy of treatment with autologous DCs and CIK cells when administered to these patients in combination with low-dose chemo therapy.

METHODS

DCs and CIK cells obtained at initial diagnosis of AML in elderly patients were cultured and used in combination with low-dose chemo therapy to treat these patients (immunotherapy group). Elderly patients with AML treated only with low-dose chemotherapy served as the control. Before treatment and on day 7 after treatment with autologous DCs and CIK cells, T cell subsets and cytokine levels were evaluated in the immunotherapy group.

RESULTS

A total of 21 elderly patients with AML were included in the immunotherapy group and 23 in the control group. The clinical efficacy in the immunotherapy group was greater than in the control group. The percentages of T cell subsets and cytokine levels after immunotherapy treatment were significantly higher than before the treatment.

CONCLUSION

Immuno therapy with autologous DCs and CIK cells was found to be a promising candidate for treatment of AML in elderly patients.

Effects of Enzyme Complex Supplementation to a Paddy-based Diet on Performance and Nutrient Digestibility of Meat-type Ducks

Paddy rice is rarely used as a feed because of its high fiber content. In this study, two experiments were conducted to study the effects of supplementing an enzyme complex consisting of xylanase, beta-glucanase and cellulase, to paddy-based diets on the performance and nutrient digestibility in meat-type ducks. In the both experiments, meat-type ducks (Cherry Valley) were randomly assigned to four treatments. Treatment 1 was a basal diet of corn-soybean; treatment 2 was a basal diet of corn-paddy-soybean; treatment 3, had enzyme complex added to the corn-paddy-soybean basal diet at levels of 0.5 g/kg diet; and treatment 4, had enzyme complex added to the corn-paddy-soybean diet at levels of 1.0 g/kg diet. The results showed that the enzyme complex increased the ADG, and decreased the ADFI and F/G significantly (p<0.05) in the ducks, and the ADFI for the ducks fed the corn-paddy-soybean diet showed no difference compared to the ducks fed corn-soybean diets at all stages of the experiment (p<0.05). When corn was partially replaced by paddy, the digestibility of CP and NDF was decreased and increased, respectively (p<0.05), and the level of enzyme complex had a significant effect on both CP and NDF digestibility (p<0.05). As for the AME, addition of enzyme complex increased it significantly (p<0.05), but both diet types and levels of enzyme complex had no effect (p>0.05). The outcome of this research indicates that the application of enzyme complex made up of xylanase, beta-glucanase, and cellulase, in the corn-paddy-soybean diet, can improve performance and nutrition digestibility in meat-type ducks.

Randomized controlled trial for Salvia sclarea or Lavandula angustifolia: differential effects on blood pressure in female patients with urinary incontinence undergoing urodynamic examination

OBJECTIVES

The aim of this study was to investigate the effect of inhalation of Salvia sclarea (clary sage; clary) or Lavandula angustifolia (lavender) essential oil vapors on autonomic nervous system activity in female patients with urinary incontinence undergoing urodynamic assessment. STUDY DESIGN, LOCATION, AND SUBJECTS: This study was a double-blind, randomized, controlled trial carried out in 34 female patients with urinary incontinence.

OUTCOME MEASURE

The subjects were randomized to inhale lavender, clary, or almond (control) oil at concentrations of 5% (vol/vol) each. Systolic blood pressure, diastolic blood pressure, pulse rate, respiratory rate, and salivary cortisol were measured before and after inhalation of these odors for 60 minutes.

RESULTS

The clary oil group experienced a significant decrease in systolic blood pressure compared with the control (p=0.048) and lavender oil (p=0.026) groups, a significant decrease in diastolic blood pressure compared with the lavender oil group (p=0.034) and a significant decrease in respiratory rate compared with the control group (p<0.001). In contrast, the lavender oil group tended to increase systolic and diastolic blood pressure compared with the control group. Compared with the control group, inhalation of lavender oil (p=0.045) and clary oil (p<0.001) resulted in statistically significant reductions in respiratory rate.

CONCLUSIONS

These results suggest that lavender oil inhalation may be inappropriate in lowering stress during urodynamic examinations, despite its antistress effects, while clary oil inhalation may be useful in inducing relaxation in female urinary incontinence patients undergoing urodynamic assessments.

The essential oil of Citrus bergamia Risso induces vasorelaxation of the mouse aorta by activating K(+) channels and inhibiting Ca(2+) influx

OBJECTIVES

The aim of this study was to explore the effect of the essential oil of Citrus bergamia Risso (bergamot) on mouse blood vessels and to analyse the mechanism of this effect from a pharmacological perspective.

METHODS

We investigated the effect of bergamot essential oil (BEO) on vascular tonus during contraction of mouse aorta induced by prostaglandin F2α (PGF2α ) or noradrenaline (norepinephrine).

KEY FINDINGS

In mouse aortic rings, BEO (0.01, 0.1 and 0.2% v/v) reduced contraction in a dose-dependent manner, and relaxed the vascular tonus induced by PGF2α . No significant difference in the extent of vasorelaxation induced by 0.1% (v/v) BEO was evident when rings with intact endothelium and endothelium-denuded rings were compared. When aortic rings were suspended in a medium that was Ca(2+) -free but contained 80 mm KCl, addition of CaCl2 (1, 2.5 or 5 mm) induced contraction in a dose-dependent manner. However, addition of Ca(2+) after incubation of the rings with BEO strongly suppressed CaCl2 -induced contraction. Further, the K(+) -channel blocker tetraethylammonium chloride partially blocked BEO-induced vasorelaxation.

CONCLUSIONS

Our findings suggest that BEO may induce endothelium-independent vasorelaxation by regulating the vascular tone of smooth muscle. Activation of K(+) channels and inhibition of Ca(2+) influx may be involved in vasorelaxation of mouse aorta elicited by BEO.

Bryostatin-1 promotes long-term potentiation via activation of PKCα and PKCε in the hippocampus

Activation of protein kinase C (PKC) by bryostatin-1 affects various functions of the central nervous system. We explored whether bryostatin-1 influenced synaptic plasticity via a process involving PKC. Our purpose was to examine whether bryostatin-1 affected the induction of hippocampal long-term potentiation (LTP) in Schaffer-collateral fibers (CA1 fibers) of the hippocampus, and/or influenced the intracellular Ca(2+) level of hippocampal neurons. We also determined the PKC isoforms involved in these processes. We found that bryostatin-1 strongly facilitated LTP induction, in a dose-dependent manner, upon single-theta burst stimulation (TBS). Further, intracellular Ca(2+) levels also increased with increasing concentration of bryostatin-1. The facilitative effects of bryostatin-1 in terms of LTP induction and enhancement of intracellular Ca(2+) levels were blocked by specific inhibitors of PKCα and PKCε, but not of PKCδ. Our results suggest that bryostatin-1 is involved in neuronal functioning and facilitates induction of LTP via activation of PKCα and/or PKCε.

A systematic review of enhanced recovery protocols in colorectal surgery

INTRODUCTION

Colorectal surgery has been associated with a complication rate of 15-20% and mean post-operative inpatient stays of 6-11 days. The principles of enhanced recovery after surgery (ERAS) are well established and have been developed to optimise peri-operative care and facilitate discharge. The purpose of this systematic review is to present an updated review of peri-operative care in colorectal surgery from the available evidence and ERAS group recommendations.

METHODS

Systematic searches of the PubMed and Embase™ databases and the Cochrane library were conducted. A hand search of bibliographies of identified studies was conducted to identify any additional articles missed by the initial search strategy.

RESULTS

A total of 59 relevant studies were identified. These included six randomised controlled trials and seven clinical controlled trials that fulfilled the inclusion criteria. These studies showed reductions in duration of inpatient stays in the ERAS groups compared with more traditional care as well as reductions in morbidity and mortality rates.

CONCLUSIONS

Reviewing the data reveals that ERAS protocols have a role in reducing post-operative morbidity and result in an accelerated recovery following colorectal surgery. Similarly, both primary and overall hospital stays are reduced significantly. However, the available evidence suggests that ERAS protocols do not reduce hospital readmissions or mortality. These findings help to confirm that ERAS protocols should now be implemented as the standard approach for peri-operative care in colorectal surgery.